noname wrote:
Thanks for the replies, Dave, Rick, and Jim. Since my ideas didn't go
over so well, perhaps it's best to just describe my setup and then
listen to any suggestions. Since I'm not an electrical engineer, do
try to keep things simple.

As I said earlier, the radio and speaker are both connected to the
house ground through their power cords. I've also installed an
inverted V dipole in the back yard (the only place it will fit). The
center (feedpoint) of the antenna is attached to the roof on the
second floor (about twenty feet above the ground) and the two ends run
out to the two corners of the backyard. That's the best I can
accomplish given local antenna restrictions.

My house is located on a hill with a top floor entrance and living
area. Below that is another floor level with the backyard, with a
basement below that.

The radio will be located in the living room on the top floor, again
one floor above the backyard. The coax (RG-8X) will run out a window
on the second floor to the center (feedpoint) of the antenna attached
to the roof just outside (a run of roughly 15-ft).

Now, where (if any) should I add grounding to that setup? I was going
to add a lightning arrester to the coax just before it enters the
house (fed into two ground rods), but will forego that since none seem
overly thrilled about the idea.

By the way, a Yeasu technician once recommended salting ground rods to
resolve a poor grounding situation at the time, so I've been doing
that ever since (can't hurt), especially during the dry summer months.
Adding water is pretty obvious, so didn't think I needed to spell that
out, Dave.

stewart / w5net

Do you have metal water pipes upstairs with continuity to a spot near
the ground rods downstairs? If so you can run a strap to your shack
upstairs, and another from the water pipe to the ground rods downstairs.

You need an RF ground (as the safety ground is the 3 prong Edison.) MFJ
makes an artificial ground. Do you use a balun at the antenna
feedpoint? How do you tune the inverted-V?

d

Do you have metal water pipes upstairs with continuity to a spot near
the ground rods downstairs? If so you can run a strap to your shack
upstairs, and another from the water pipe to the ground rods downstairs.


bad plan.

1) Water pipes may or may not have good electrical conductivity.
2) You're asking for leakage current to flow in the pipes: corrosion is
one possibility, shocks to people touching the pipes or plumbing is another.
3) If you also have the third wire ground to chassis, good chance you've
now created a big receiving loop consisting of the pipes and your house
electrical systems. Not good.

4) Using plumbing systems for electrical safety bonding/grounding is not
recommended in any of the recent editions of the electrical code, and is
certainly not a good idea for RF currents.



You need an RF ground (as the safety ground is the 3 prong Edison.) MFJ
makes an artificial ground.

If it's a coax fed antenna, there should be no need for any sort of RF
ground in the shack.


Do you use a balun at the antenna
feedpoint? How do you tune the inverted-V?

Good RF chokes on the coax at the feedpoint and at the point of entry
would go a long way to eliminating any "RF in the shack" problems. A
couple 2.4" 31 mix cores with half a dozen turns on them, for instance.

Whether the V is tuned or not won't have any effect on RFI or grounding.

Jim Lux wrote:


Do you use a balun at the antenna
feedpoint? How do you tune the inverted-V?

Good RF chokes on the coax at the feedpoint and at the point of entry
would go a long way to eliminating any "RF in the shack" problems. A
couple 2.4" 31 mix cores with half a dozen turns on them, for instance.

Whether the V is tuned or not won't have any effect on RFI or grounding.

A BalUn would help a lot.

Since we are sticklers for the NEC, Homey needs a #6 wire from where the
transmission line enters the dwelling to an 8' copper clad rod driven
into the earth, as close as practicable.

"dave" wrote

A BalUn would help a lot.

For what? If the antenna system is balanced (as are dipoles, inherently), I
seriously doubt a balun would be good for anything.

Howard Lester wrote:
"dave" wrote

A BalUn would help a lot.

For what? If the antenna system is balanced (as are dipoles, inherently), I
seriously doubt a balun would be good for anything.



He's feeding it with coax, so it's not just a good idea, it's required.

The antenna is balanced, the feedline is not. He stated the feedline is
RG-8X.

tom
K0TAR

"Tom Ring" wrote

He's feeding it with coax, so it's not just a good idea, it's required.

The antenna is balanced, the feedline is not. He stated the feedline is
RG-8X.

I know that, and just because it's balanced to unbalanced, it's not
*required.* The antenna system can work just fine without one. In some
cases, at least according to the late Lew McCoy, it can do more harm than
good. If the antenna system is inherently unbalanced due to one leg being,
say, in greater proximity to metal and other objects, then I would consider
using some kind of balun or choke system.

Howard Lester wrote:
"Tom Ring" wrote

He's feeding it with coax, so it's not just a good idea, it's required.

The antenna is balanced, the feedline is not. He stated the feedline is
RG-8X.

I know that, and just because it's balanced to unbalanced, it's not
*required.* The antenna system can work just fine without one. In some
cases, at least according to the late Lew McCoy, it can do more harm than
good. If the antenna system is inherently unbalanced due to one leg being,
say, in greater proximity to metal and other objects, then I would consider
using some kind of balun or choke system.



http://www.bunkerofdoom.com/lit/bal_...baltransys.pdf

Howard Lester wrote:
"Tom Ring" wrote

He's feeding it with coax, so it's not just a good idea, it's required.

The antenna is balanced, the feedline is not. He stated the feedline is
RG-8X.

I know that, and just because it's balanced to unbalanced, it's not
*required.* The antenna system can work just fine without one. In some
cases, at least according to the late Lew McCoy, it can do more harm than
good. If the antenna system is inherently unbalanced due to one leg being,
say, in greater proximity to metal and other objects, then I would consider
using some kind of balun or choke system.



Well, I'm not going to argue with someone who thinks that placing a
balun between an unbalanced feed and a balanced load could ever possibly
do more harm than good.

It would be a utter waste of time.

tom
K0TAR

Howard Lester wrote:
"Tom Ring" wrote

He's feeding it with coax, so it's not just a good idea, it's required.

The antenna is balanced, the feedline is not. He stated the feedline is
RG-8X.

I know that, and just because it's balanced to unbalanced, it's not
*required.* The antenna system can work just fine without one. In some
cases, at least according to the late Lew McCoy, it can do more harm than
good. If the antenna system is inherently unbalanced due to one leg being,
say, in greater proximity to metal and other objects, then I would consider
using some kind of balun or choke system.



Sorry, I forgot to add

PLONK!

tom
K0TAR

Tom Ring wrote:

He's feeding it with coax, so it's not just a good idea, it's
required.

The antenna is balanced, the feedline is not. He stated the
feedline is RG-8X.


The assembly instructions for the antenna say...

The antenna is "..designed to be used with
50 ohm coax cable. No balun is required for
proper operation.

If RF on the coax is a problem, simply wind
a "choke balun" with the coax that's used for
your feedline. Wind approx 8 turns, at about
an 8 inch diameter and tape (with outdoor rated
black electrical tape), like a donut, and place
this "donut" near the feedpoint of the antenna.
You should leave about 2 foot of your coax
sticking out of this "donut" for connection to
the antenna. Then attach the end of your
coax to the antenna connector on the center
insulator, with the coax connector that is
already on your feed line."

In other words, a scramble-winding choke near the antenna's feedpoint,
which I'll add if RF becomes an issue. As stated in my first message
("don't believe RF is an issue with a dipole," which should probably
read "major issue"), I'm much more concerned with safety and lightning
protection.

stewart / w5net